Gas turbine equipment and method of controlling such equipment

ABSTRACT

A multiple-rotor gas turbine engine comprising a turbocompressor, a combustion chamber and a turbine having a high pressure part and a low pressure part, the low pressure part driving the turbocompressor while the high pressure part delivers the output power.

United States Patent [191 Kyrklund Get. 16, 1973 [54] GAS TURBINE EQUIPMENT AND METHOD 3,621,657 11/1971 Jurisch et a1 60/3925 0 CONTROLLING SUCH EQUIPMENT 3,325,994 6/1967 Zaba et a1 60/39.25 3,508,395 4/1970 Sebestyen 60/3925 [75] Inventor: Ben Harald Kyrklund, Finspang,

Swede" FOREIGN PATENTS OR APPLICATTONS [73] Assignee: Stal-Laval Turbin AB, Finspang, 1,126,906 12/1956. France 60/3916 Sweden 186,162 11/1963 Sweden 60/3925 [22] Filed: Dec. 17, 1971 Prima ExaminerCarlton R. Cro 1e 21 A LN .1209120 Y 1 pp 0 Assistant ExaminerWarren Olsen AttorneyEric Y. Munson et a1. [30] Foreign Application Priority Data Feb. 1, 1971 Sweden 1175/71 57 ABSTRACT [52] U.S. Cl 60/39.l6 R, 60/3925, 60/3928 1 [51] Int. Cl. F026 3/10 A multiple rotor gas turbine engine comprising a tun [58] Field of Search 60/3916, 39.25, bocompressor a combustion chamber and a turbine 60/3917 3928 having a high pressure part and a low pressure part, the low pressure part driving the turbocompressor [56] References (med while the high pressure part delivers the output power.

UNITED STATES PATENTS 3,686.860 8/1972 White 60/3916 3 Claims, 7 Drawing Figures h a a: ,2 LILILIUUUUUU PATENTEU 1 SW 3.7 6 5.18 9

' SHEET 1 0F Fig.1

Ben Harald Kyrklund IN VENT OR.

BY ERIC Y. MUNSON and ROBERT W. FIDDLER FATENTEDHBT 1 Elm 765, 1 89 sumenrz Fig. 45

Ben Harald Kyrklund INVENTOR.

ERIC Y. MUNSON and ROBERT W. FIDDLER GAS TURBINE EQUIPMENT AND METHOD OF CONTROLLING SUCH EQUIPMENT BACKGROUND OF THE INVENTION In conventional, single shaft gas turbines there is a predetermined upper limit for maximum power output for economical operation and this limit seems to lie somewhat below 100 MW, due to the fact that the low pressure part in the turbine at full load cannot pass therethrough a quantity of gas which corresponds to the quantity of air delivered from the compressor rotating at the same speed. It has therefore been suggested to design the turbine section with two shafts, in which the compressor and low pressure part of the turbine rotate at a different speed from that of the high pressure part of the turbine. In this manner sufficientquantity of gas can pass through the low pressure part, and the lower the speed the greater the quantity of gas. This principle permits a considerably higher limit for the economic maximum power output.

However, the two-shaft gas turbine described above has hardly been used in practice because of the difficulties in achieving a suitable-control system.

SUMMARY OF THE INVENTION According to the invention it is now proposed to insert a control member in theform of a system of pivotally mounted, controllable inlet guide vanes to control the gas turbine equipment.

By turning the vanes of said system, the inlet direction of the gas in relation to the rotating vanes of the high pressure part of the turbine may be varied, and the opening angle a of the guide vanes may be suitably adjusted in relation to the other control parameters of the equipment, namely the speed n of the low pressure rotor, the output power E and the temperature T of the combination chamber or the fuel injection q. Of these parameters, the output power E can be regulated either by means of the opening angle of the inlet vanes or the fuel supply q or the temperature T, whereas the other two parameters are coordinated by means of the'control equipment.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will'be further described with refer ence to the accompanying drawings, in which FIG. l'shows a gas turbine equipment according to the invention, whereas FIGS. 2a and 2b show the system of inlet guide vanes for the high pressure part in detail,

FIGS. 3a and 3b and FIGS. 4a and 4b show various control circuits for the equipment according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. I shows a gas turbine engine comprisinga turbocompressor l, a combustion chamber 2 and a turbine section comprising a high pressure part 3 and a low pressure part 4. The-latter drives the turbo compressor via a shaft 5, whereas the high pressure part delivers the output power to the generator 6 via a shaft 7. The compressed air from the compressor 1 is supplied to the combustion chamber 2 through a conduit 8. Fuel is supplied to the combustion chamber via a control valve 9.

The low pressure part is provided with at least one rotating vane wheel and its r.p.m. is measured with the help of a tachometer-generator 12. The high pressure part is provided with at least one disc carrying a row of blades row 10, in front of which is arranged a system '11 of inlet guide vanes, Le, a system of guide vanes having variable opening angles a, as can be seen-in more detail in FIG. 2b.

FIGS. 2a and 2b show part of the inlet guide vane system 11 with the blade row 10, FIG. 2a showing these parts seen from the side in an axial section and FIG. 2b showing the same parts seen from the outside in radial direction. The vane system 11 consists of a system of pivotable guide vanes 25, each arranged on a shaft 22 provided with a transverse pin 23. These transverse pins fit into holders on the inside of a cylindrical ring 24 which can be turned by a servo-device 19. The turning of the ring 24 also turns the transverse pins 23 and consequently the guide vanes 25 so that their opening angles a may be varied.

The variables which are coordinated in relation to each other in the control system of the turbine equipment are the output power E, the rpm. n of the low pressure part,the fuel supply q and the opening angle a for the inlet guide vane system of the high pressure part, as mentioned previously. These four parameters can be regulated in accordance with different principles, as exemplified in FIGS. 3a, 3b and FIGS. 4a, 4b.

According to FIG. 3a, the valve 9 for the fuel supply is regulated by means of a servo-device 17 from a frequency/power control circuit. The generator 6 is for this purpose provided with a frequency gauge 20 and a power gauge 13. For the output power there is a desired value indicator in the form ofa potentiometer 15. The true value and the desired value for the power are supplied to an amplifier 14, the output signal of which is supplied to a second amplifier 16 connected in parallel with the signal from the frequency gauge 20. In this way the fuel supply through the valve 9 is regulated in accordance with the desired frequency and power.

The angle a of the inlet guide vane system is controlled by the speed n of the low pressure part in accordance with FIG. 3b so that each value for n is allotted a certain angle a. The speed n is measured by a tachometer-generator 12, the output signal of which is converted in an amplifier 18 to form the control signal for the servomotor 19 which adjusts the angle a of the guide vane system.

Another possibility is for the fuel supply to be regulated by the speed n'of the low pressure part so that the speed is kept constant. FIG. 4b shows how the speed is measured by a tachometer-generator 12, the output signal of which is compared in the amplifier 16 with a desired value from a transducer 21. The output signal of the amplifier provides the control signal for the servomotor 17 of the fuel valve 9.

The power of the turbine equipment is controlled with the help of the angle a of the inlet guide vane system according to FIG. 4a, this figure showing how the servomotor 19 of the system is affected by the frequency/power control circuit 20, 13 15.

I claim:

1. A multiple gas turbine engine comprising a turbocompressor, a combustion section and a turbine section having a vaned high pressure part and a low pressure part, said low pressure part comprising a shaft for driving said compressor, said high pressure part driving a power transmitting shaft; a system of pivotally mounted inlet guide vanes for controlling the angle of deflection of the gases from the combustion section relative to the vanes of said high pressure part; a servomotor for actuating said inlet guide vanes; an adjustable fuel valve for said combustion section; regulating means for said fuel valve and for said servomotor; one of said regulating means being adapted to be controlled from a reference value means for the desired power transmission; tachometer means connected to said low pressure part, said tachometer means being effective to control the other of said regulating means.

2. A multiple gas turbine engine as claimed in claim 1, in which the input side of said regulator means for said fuel valve is connected to said reference value means for the desired output power; said regulator means for said servomotor for said system of inlet guide vanes is connected to said tachometer means; the deflection angle of said inlet guide vanes being a function of the number of revolutions of said low pressure part.

3. A multiple gas turbine engine as claimed in claim 1, in which said regulator means for said servomotor for said system of inlet guide vanes are connected to said reference value means; said regulator means for said fuel valve being connected to said tachometer means; a reference value means being connected to the input side of said last mentioned regulator means. 

1. A multiple gas turbine engine comprising a turbocompressor, a combustion section and a turbine section having a vaned high pressure part and a low pressure part, said low pressure part comprising a shaft for driving said compressor, said high pressure part driving a power transmitting shaft; a system of pivotally mounted inlet guide vanes for controlling the angle of deflection of the gases from the combustion section relative to the vanes of said high pressure part; a servomotor for actuating said inlet guide vanes; an adjustable fuel valve for said combustion section; regulating means for said fuel valve and for said servomotor; one of said regulating means being adapted to be controlled from a reference value means for the desired power transmission; tachometer means connected to said low pressure part, said tachometer means being effective to control the other of said regulating means.
 2. A multiple gas turbine engine as claimed in claim 1, in which the input side of said regulator means for said fuel valve is connected to said reference value means for the desired output power; said regulator means for said servomotor for said system of inlet guide vanes is connected to said tachometer means; the deflection angle of said inlet guide vanes being a function of the number of revolutions of said low pressure part.
 3. A multiple gas turbine engine as claimed in claim 1, in which said regulator means for said servomotor for said system of inlet guide vanes are connected to said reference value means; said regulator means for said fuel valve being connected to said tachometer means; a reference value means being connected to the input side of said last mentioned regulator means. 